BOM with varying number of items

Greetings Friends !

Being Electric Distribution Panel Manufacturer, I am faced with a situation as below:

I use Template BOM in Manufacturing Module.

One Item, Contactor 750V 50Amp is used with NO-NC Blocks.

One manufacturer supplies this item with NO-NC Blocks pre-fitted and has one Part# for item.
Another manufacturer supplies the contactor and NO-NC Blocks separately each with its own part#.

I contemplated defining a “Sub-BOM Template” with two items i.e.;

  1. Contactor 750V 50Amp (Template Item)
  2. No-NC Blocks (Template Item)

BUT, this could lead to errors if the person making Work order does not pay attention to when to OR not to use the NO-NC Blocks. I want to de-skill this selection process… the Sub BOM lengh is varying in nature.

I hope there is a solution to this issue and would highly appreciate help.

Thanks in advance